On 2024/9/4 12:29, Christoph Hellwig wrote: > On Tue, Sep 03, 2024 at 11:49:28AM -0600, Jens Axboe wrote: >> The elephant in the room here is why an 80M completion takes 100 msec? >> That seems... insane. >> >> That aside, doing writes that big isn't great for latencies in general, >> even if they are orders of magnitude smaller (as they should be). Maybe >> this is solvable by just limiting the write size here. >> >> But it really seems out of line for a write that size to take 100 msec >> to process. > pagecache state processing is quite inefficient, we had to limit > the number of them for XFS to avoid latency problems a while ago. > Note that moving to folios means you can process a lot more data > with the same number of completion iterations as well. I'd suggest > the submitter looks into that for whatever file system they are using. > hi Christoph, The F2FS file system is used on the smartphone, and end_io uses page traversal instead of folio traversal. I will confirm the plan to migrate to folio. Thank you! Thanks Zhang
